This invention concerns hard cover tonneaus for the cargo box of pick-up trucks. In such tonneau covers, one or more panel sections are mounted on the side walls of the cargo box, and are hinged to allow raising of one end or side of the cover sections which may also be disconnected from the cargo box for removal. Such covers have typically been specifically been designed for a particular cargo bed configuration, and have involved heavy panels of fiber glass reinforced molded resins.
Such hard covers are typically fit over plastic protection covers on the cargo box, and hinged to be raised for access to the cargo area, with gas struts used to support the weight of the opened cover.
The heavy weight of these tonneau covers has been an increasing disadvantage as this reduces fuel economy and truck net payload capacity.
The proliferation of pick-up truck cargo box configurations has led to increased costs due to the need for a greater number of custom designed covers.
U.S. Pat. No. 6,082,806 suggests a construction using a tubular frame and thin panels fixed to the frame, allowing easy modification to fit various cargo bed sizes.
However, such an approach requires painting of the aluminum frame. The cover panel affixed to the frame is subject to buckling due to temperature induced expansion and is difficult to replace if damaged.
It would be desirable to be able to match the quality of cover finish to vehicle finish, but this has heretofore not been possible due to the difficulty in obtaining a distortion free cover surface acceptable to the automobile manufacturers.
Another difficulty has to do with the service wear on the components and the mating sheet metal surfaces due to the severe deflections of the cargo box during driving of the truck, particularly over rough roads and long periods of time. Such wear occurs in the striker bars and hinges, and also where a cover seal scrubs against the cargo box painted sheet metal.
Another problem is found in draining water from the cover to prevent leakage into the cargo box. While attempts have been made to seal all the joints, some seepage still occurs, and any bonding of a cover panel needed to create a seal will create thermally induced distortions as mentioned above.
Installation and removal of the tonneau cover is often time consuming due to the need to accurately align the cover with the cargo box and the need for installing or removing numerous cover mounting components and fasteners.
It is the object of the present invention to provide a hard tonneau cover for a pick-up truck cargo box which is light weight and low in cost to manufacture, but which has a high quality appearance compatible with the factory finish of the truck body.
It is another object of the present invention to provide a tonneau cover which can be readily sized and configured to be matched to a great variety of cargo box sizes and configurations, and having an easily adjustable mounting system so that the cover may be readily installed in the proper position on the cargo box.
It is a further object to provide a hard tonneau cover which can withstand extended service in the field while maintaining proper function of the components, and a good appearance while avoiding excessive wear of the truck body finish.
Yet another object is to provide a hard tonneau cover which incorporates a water drainage system which directs water off the cover to prevent any water from penetrating into the cargo box, and which channels any seepage along a path formed in the cover components away from the cargo area.